Question

A can of coke has a small pinhole leak in it. The coke sprays vertically into the air to a height of 0.5 m. What is the pressure inside the can of coke? Assume the time spent to the top of the spray from the pinhole is 0.7 second and the coke specific gravity is 1.11

Answer 1

Inside the can there is no velocity, and hence the velocity head and elevation head is zero assuming the datum just inside the hole. So thia pressure head first converts to velocity head and then to the elevation head at the top most point of the spray.

As per Bernaulli's theorem, total head = constant

Hence, pressure head inside the can = elevation head at top of spray =  0.5 m,

Hence pressure = unit weight of coke× 0.5 = 1.11 × 9810 × 0.5 = 5444.55 Pascal = 5.44 kPa (gage)